Preparation method of silicon carbide power diode device

Abstract

The invention relates to a preparation method of a silicon carbide power diode device. The preparation method comprises the following steps: growing a SiC epitaxial layer with an N type active regionon a first surface of a SiC substrate; depositing a first barrier layer on the surface of the SiC epitaxial layer, opening an injection window in the N type active region through etching, and performing ion injection in the injection window of the N type active region; through high-temperature activation, forming P type regions arranged at intervals in the N type active region; and covering a first metal layer forming ohmic contact with the P type region with a second metal layer, so that the first metal layer is prevented from being corroded by a BOE solution in the process of removing the second barrier layer through wet etching, the integrity of the first metal layer is greatly guaranteed, the problem that metal particles contaminate a device is avoided, the reliability risk caused by metal particle contamination is reduced, and the device manufacturing yield is greatly improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a method for preparing a silicon carbide power diode device. Background technique [0002] Compared with traditional Si-based devices, SiC devices have the characteristics of faster operating frequency, lower operating loss, and higher operating temperature. As a representative device of SiC power devices, SiC diodes are widely used in power supplies, new energy vehicles and other fields. [0003] Due to the difference in the characteristics of SiC material and Si material, the process difference in its device preparation is caused. For example, if the temperature of the high-temperature activation process of SiC devices reaches above 1600°C, it is necessary to make a protective layer on the front and back of the wafer to prevent the precipitation of carbon particles and affect the interface state of the device. [0004] In the preparation of SiC MPS (Merged PiN Sc...

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Problems solved by technology

The BOE (Buffered Oxide Etch) solution used in wet etching, that is, the buffered oxide etching solution, will cause corrosion to the front ohmic metal, and the metal particles will be contaminated with the BOE solution in various positions of the device, including the active area or The terminal area forms a leakage channel, causing electrical failure of the device, and even affecting the reliability of the device

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